Development Of The Model Of The Atom

Question 1

What did John dalton do ?

Answer 1

Around the start of the 19th century he described atoms as solid spheres for the first time

Question 2

What did JJ Thomson do ?

Answer 2

1897, he does the plum pudding model: the atom is a ball of positive charge with negative electrons embedded in it. He named it the plum pudding model.

Question 3

What did Rutherford do ?

Answer 3

1909, alpha scattering experiment: he fired alpha particles at gold foil, most of the alpha particles went straight through showing it was mainly empty space. mass concentrated at the centre; the nucleus is charged. Most of the mass is in the nucleus. most atoms are empty space and the electron orbits the nucleus this was the first nuclear model.

Question 4

What did Niels Bohr do?

Answer 4

Around 1911, electrons are in shells orbiting the nucleus at a specific distance

Question 5

What did James Chadwick do ?

Answer 5

Around 1940 he discovered that there are neutrons in the nucleus.